905MASONRY UNITS

905.01Clay or Shale Brick

Brick shall be in accordance wi th the following specifications.

Sewer brick shall be in accordance with ASTM C32, grade SS.

Manhole brick shall be in accordance with ASTM C32, grade MS. 10

Building brick shall be in accordance with ASTM C62, grade SW.

905.02Concrete Brick

Concrete brick intended for use in cons truction of manholes, catch basins, and similar structures, or as building bricks, shall be in accordance with ASTM C55.

905.03Concrete Masonry Blocks

Concrete masonry blocks may be rectangular or segmented and, when specified, 20 shall have ends shaped to provide interlock at vertical joints. Solid masonry units shall be in accordance with ASTM C139. Hollow load-bearing masonry units shall be in accordance with ASTM C90, normal weight.

905.04Precast Concrete Curbing

Precast concrete curbing shall consist of precast portland cement concrete curb units constructed to the length, shapes, and other details shown on the plans. These units shall be reinforced with steel reinforcement when shown on the plans. Steel reinforcement shall be in accordance with 910.01.

When required for driveways, crossings, closures, or for other reasons a depressed or modified section of curb is indicated, curbing with the required modification shall be furnished.

905.05Detectable Warning Surfaces

The detectable warning surface in concre te curb ramps shall be constructed using materials from the QPL of De tectable Warning Surfaces, wh ich is maintained by the Department’s Division of Materials and Tests. A surface manufacturer wishing to add a product to the QPL shall comply with Procedure L of ITM 806.

similarly naturally occurring earthy substance, subjected to heat treatment at elevated temperatures to form bricks or pavers. The dimensions of the brick shall be 8 in. in length, 4 in. in width including any spacing lugs. The thickness of the brick shall be 2 in., excluding dome height and edge chamfers. The truncated domes on 905.01

the surface shall be formed integral with the main body of the detectable warning surface and be pr esent on the brick prior to heat treatment. The size and physical requirements of the bricks shall be in accordance with ASTM C902 for weather and traffic environment 50 classifications Class SX, Type II, respectively. The truncated domes may be ground off to meet the cap thickness requirement for compressive strength testing.

in color and shall be uniform throughout the brick. The color will be determined from the average of five color readings for detectable warning surfaces when measured at the top surface between the raised truncated domes and determ ined in accordance with ASTM E1349, CIE Illuminant D65, 10° Standard Observer, using 60 instrument geometry of 45°/0°, and the CIE L* a* b* color system. The tested bricks shall be within the limits as follows:

Minimum Maximum L* 35.0 50.0 a* 6.0 36.0 b* 0.0 30.0

The value of a* shall not be less than 90% of the value of b*. The color difference of any installed brick after one year of exposure or of an individual detectable warning surface from the average color for any product or model from a manufacturer shall not be greater WKDQǻ(XQLWV7KHFRORUVKDOOEHXQLIRUPWKURXJKRXWWKH detectable warning surfaces. 70

gray iron in accordance with AASHTO M 105, Class No. 30A as a minimum. The truncated domes shall be as shown on the plans. The tops of the domes and the space between domes shall have a non- slip textured surface. The minimum thickness of the casting shall be 0.20 in. The minimum thickness shall not be measured within the area of integral reinforcing ribs or bracing, domes, or the textured surface.

and 0.26 in. The design values shall be within the ranges identified in the Standard Drawings. No more than two truncated domes per surface may be out of tolerance for dimensions.

accordance with 905.05(a) or cast iron in accordance with 905.05(c) will be considered. The detectable warning surfaces shall meet the 905.05

color requirements of 905.05(b) and the truncated dome requirements of 905.05(d). 90

905.06Precast Concrete Un its Not Otherwise Covered

These units shall be cast in substantial pe rmanent steel forms. Structural concrete shall attain a minimum 28-day compressive strength of 3,000 psi as determined in accordance with AASHTO T 22. When air-entrained concrete is specified, it shall have an air content of from 5% to 8% by volume. The precast units shall be cured in accordance with AASHTO M 170. Water absorption of individual cores taken from such units shall not exceed 9%. Additional reinforcement shall be provided as needed to handle the precast units.